The intro and outro paragraphs support HTML, including text formatting and hyperlinks. We're working on a style guide, but for now, if you want to add hosted images, we recommend using a 560px-wide JPG, and hosting the image where it will never be deleted, moved, or renamed.
If you notice alignment issues, try adding "display: block", e.g.:
<img src="the link to image goes here" style="display: block;">